1. Technical Field
The present invention relates to a screen that reflects projection light from a projector or other projection apparatus in front of the screen to display a projected image, and a projection system using such a screen.
2. Related Art
There is a screen comprised of integrated microlenses and reflection surfaces with the orientation of the reflection surfaces disposed behind the microlenses being inclined to the center normal line of the screen, in particular, a screen in which the inclination angle is gradually changed from the central portion of the screen toward the periphery thereof (see JP-A-3-156435). There is another screen in which a lenticular lens is formed on the surface of the screen and the cross-sectional shape of the lenticular lens is non-arcuate (see JP-A-5-72631).
When a reflective screen that reflects projection light from a projector or other projection apparatus in front of the screen to display a projected image is used, for example, to reflect the projection light incident at a large angle of incidence in the forward direction, each of the reflection surfaces needs to be positioned close to the lens surface of the corresponding microlenses because the reflection surface is desirably disposed in front of the focus position of the microlenses and other reasons in order to efficiently scatter and reflect the incident projection light in the forward direction at an appropriate angle of view. In this case, when the reflection surfaces are too close to the lens surfaces, a series of portions where the reflection surfaces are close to the lens surfaces are significantly thin, probably resulting in a manufacturing problem and a strength problem.
As another problem, when a reflective screen is used, part of external light, which is unwanted light, may be reflected toward a person who is looking at the screen, and the reflected external light may reduce the contrast of a projected image.